From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from eggs.gnu.org ([208.118.235.92]:55081)
	by lists.gnu.org with esmtp (Exim 4.71)
	(envelope-from <rth7680@gmail.com>) id 1TOdHj-0007w0-CC
	for qemu-devel@nongnu.org; Wed, 17 Oct 2012 19:44:24 -0400
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)
	(envelope-from <rth7680@gmail.com>) id 1TOdHi-0008Sk-ED
	for qemu-devel@nongnu.org; Wed, 17 Oct 2012 19:44:23 -0400
Received: from mail-pa0-f45.google.com ([209.85.220.45]:52729)
	by eggs.gnu.org with esmtp (Exim 4.71)
	(envelope-from <rth7680@gmail.com>) id 1TOdHi-0008Sc-6W
	for qemu-devel@nongnu.org; Wed, 17 Oct 2012 19:44:22 -0400
Received: by mail-pa0-f45.google.com with SMTP id fb10so7708899pad.4
	for <qemu-devel@nongnu.org>; Wed, 17 Oct 2012 16:44:20 -0700 (PDT)
Sender: Richard Henderson <rth7680@gmail.com>
Message-ID: <507F42CD.6000209@twiddle.net>
Date: Thu, 18 Oct 2012 09:44:13 +1000
From: Richard Henderson <rth@twiddle.net>
MIME-Version: 1.0
References: <1350372190-32186-1-git-send-email-yeongkyoon.lee@samsung.com>
	<1350372190-32186-4-git-send-email-yeongkyoon.lee@samsung.com>
In-Reply-To: <1350372190-32186-4-git-send-email-yeongkyoon.lee@samsung.com>
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 7bit
Subject: Re: [Qemu-devel] [PATCH v6 3/3] tcg: Optimize qemu_ld/st by
 generating slow paths at the end of a block
List-Id: <qemu-devel.nongnu.org>
List-Unsubscribe: <https://lists.nongnu.org/mailman/options/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=unsubscribe>
List-Archive: <http://lists.nongnu.org/archive/html/qemu-devel>
List-Post: <mailto:qemu-devel@nongnu.org>
List-Help: <mailto:qemu-devel-request@nongnu.org?subject=help>
List-Subscribe: <https://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=subscribe>
To: Yeongkyoon Lee <yeongkyoon.lee@samsung.com>
Cc: blauwirbel@gmail.com, qemu-devel@nongnu.org, aurelien@aurel32.net

On 2012-10-16 17:23, Yeongkyoon Lee wrote:
> +    /* Code generation of qemu_ld/st's slow path calling MMU helper
> +
> +       PRE_PROC ...
> +       call MMU helper
> +       jmp POST_PROC (2b) : short forward jump <- GETRA()
> +       jmp next_code (5b) : dummy long backward jump which is never executed
> +       POST_PROC ... : do post-processing <- GETRA() + 7
> +       jmp next_code : jump to the code corresponding to next IR of qemu_ld/st
> +    */

Is this jump over jump really any better than passing next_code
as another function argument?

In 32-bit mode
	push $next_code
In 64-bit mode
	leaq next_code(%rip),%r8


r~